How to treat aquaculture wastewater —— Talking about the treatment technology of aquaculture wastewater

China's sewage treatment started late and developed rapidly, and aquaculture sewage treatment mainly adopts biochemical treatment equipment or biochemical treatment process. The biochemical treatment of sewage mainly includes contact oxidation method, AB method, A/O method, oxidation ditch, SBR, biological aerated filter and directed biological aerated filter.

Diversion biological aerated filter is a new sewage treatment process with independent intellectual property rights in China. According to the different subsequent treatment processes, it can be divided into hydrolysis-diversion biological aerated filter, anaerobic-diversion biological aerated filter, air flotation-diversion biological aerated filter, rapid sedimentation-diversion biological aerated filter, ultrasonic-diversion biological aerated filter, microwave-diversion biological aerated filter, ozone-diversion biological aerated filter and so on.

Combined with the upgrading of old sewage treatment project, nitrogen and phosphorus removal and reclaimed water reuse, AB-guided biological aerated filter was developed. A/O process-shunt biological aerated filter; A2/O method-diversion biological aerated filter; Oxidation ditch-diversion biological aerated filter; SBR guided biological aerated filter; Advanced treatment processes such as biological contact oxidation-split aeration biological filter.

Guided biological aerated filter (BAF) fully draws lessons from eight design methods, such as BAF method, contact oxidation method, biofilm method, intermittent aeration method, artificial rapid filtration method, precipitation separation method, nitrification and denitrification method, and water supply rapid filtration method, and develops a new sewage treatment process and technology.

The diversion biological aerated filter has been used in Beijing, Shandong, Hebei, Guizhou, Shanxi, Sichuan, Inner Mongolia, Heilongjiang, Jiangsu, Jilin, Henan, Hubei, Tianjin, Xinjiang and other places in China, involving sewage treatment in the fields of life, hospital, chemical industry, slaughter, food, flax, alcohol, pharmacy and pickled mustard tuber. A large number of applications have proved that the CODcr of effluent quality is generally below 20mg/L, and the lowest is 5.95 mg/L; Generally, BOD5 is below 10mg/L, and the lowest is 3.50mg/L.: SS is generally below 20mg/L, and the lowest is 6.55 mg/l.

According to the invention, sewage is aerated twice, precipitated twice and filtered twice in the same treatment tank, so that the process flow that other sewage treatment needs four tanks to complete is solved, especially under the condition of continuous water inflow, intermittent aeration and activated sludge backflow are realized, and the whole operation does not idle. Its advantages are more prominent than other treatment methods, and the treatment effect is particularly remarkable. In 2009, it was listed as "innovative project"; In February of the same year, it was listed as "environmental protection technology encouraged by the state"; 20 10 is listed as "national key new product"; 12 is also listed as the Twelfth Five-Year Plan period. The state has increased investment in environmental protection technologies recommended and encouraged in the fields of towns, villages, rural areas, industry, aquaculture, upgrading of urban sewage treatment plants, nitrogen and phosphorus removal and reclaimed water reuse. These technologies have the following advantages:

(1), technology foresight

Guided biological aerated filter (BAF) is a typical three-phase guided nitrogen and phosphorus removal reactor with high load, submerged and fixed bed. On the premise of not increasing investment, the treated sewage is superior to the discharge standard, reaching the quality of reclaimed water reuse, and the technology is forward-looking.

(2) Technological innovation

The diversion biological aerated filter makes the sewage in the same treatment tank, which solves the technological process that other sewage treatment needs four tanks to complete. The whole operation is not idle. Therefore, the process is innovative.

(3) the economy of project investment

The BOD5 volume load of the diversion biological aerated filter is 5 ~ 10 times that of the conventional secondary biological treatment, and the two aeration tanks, two sedimentation tanks and two filtration tanks are combined into one, so the project investment is economical.

(4) Stability of treatment effect

The diversion biological aerated filter has the functions of nitrification and denitrification, without worrying about sludge bulking and being affected by hydraulic load, and the treatment effect is stable.

(5) simplify the processing flow

The diversion biological aerated filter can treat sewage and achieve the quality of reclaimed water reuse without advanced treatment facilities and equipment, which simplifies the treatment process.

(6) Economy of operating expenses

The diversion biological aerated filter uses filter material to cut, block and finely break bubbles, which enhances the gas-liquid mass transfer effect, increases the contact area and time between microorganisms and air, greatly improves the oxygenation rate, reduces the power consumption and is economical in operation cost.

(7) Simple operation and management

The diversion biological aerated filter adopts PLC to realize program control operation, that is, through liquid level sensing and equipment interlocking, it can automatically start with sewage without stopping sewage; Adjust the aeration rate through the inverter chain of dissolved oxygen tester; Through free transmission, remote monitoring is realized, and the purpose of water quality monitoring and fault judgment is achieved, and the operation and management are simple.

(8) Typical nitrogen and phosphorus removal

Ammonia nitrogen is nitrated twice by autotrophic bacteria (such as nitrifying bacteria) in the lower part of the inner cone and the upper part of the outer cone, which can remove ammonia nitrogen below 3mg/L, and the lowest is less than 0.068 mg/L. The denitrification effect is typical.

Phosphorus removal in guided biological aerated filter (BAF) is a kind of phosphorus-accumulating bacteria produced in two aerobic stages, the inner cone and the outer cone. After settling at the cone bottom of BAF, it can absorb a large amount of dissolved phosphorus and discharge sludge smoothly, so the effluent phosphorus is generally less than 0.5 mg/L, and the lowest reaches 0.08 mg/L, so phosphorus removal is typical.

The invention effectively solves the technical problems of good denitrification effect and poor dephosphorization effect of the biological aerated filter. At the same time, it also solves the problem that N2 sludge is attached to A2/O in the secondary sedimentation tank and the sedimentation effect is not ideal. Increasing the reduction potential of the secondary sedimentation tank leads to the release of phosphorus, and the phosphorus removal effect is not ideal.

(9) Adaptability of temperature and operation mode

The diversion biological aerated filter can be used in 1